An organic light emitting diode (OLED) display device includes a display panel that has a plurality of signal lines and a plurality of pixels to display an image, a cover window that is positioned at the outside of a display surface of the display panel, and an adhesive layer that is positioned between the display surface and the cover window. One of the display panel and the cover window forms a concave channel in at least one corner, and the adhesive layer fills the channel.